+++ X Terminal or X Server +++

An X terminal is an electronic display terminal that communicates
with a host computer system using the X Window protocol developed at the
Massachusetts Institute of Technology.

The X Window protocol allows a program running on the host computer
system to display both formatted text and graphics on the X terminal.
Since the X Window protocol is defined to work over any TCP/IP network,
X terminals connected to the Internet can be connected to hosts
located anywhere on the Internet.

Personal computers (including both PCs and Macintoshes) can execute
programs, usually called X servers, that make them act like X Window
terminals and are frequently used as X terminals.

Note:

The terminology used to describe processes associated with X
terminals can be confusing. An X terminal is also known as
an "X display server," and the program running on the host
computer is usually known as the "X client."